the strong man decides to try different test .this time he stands in the street and pushes against the car as hard as he can when it drives towards him .altough he is pushed back ,this time he is able to stop the car after a few seconds .why was he able to stop the car this time?
When the strong man standing in the street pushes against the car from the outside, he has a direct effect of the force pushing towards him.
Initially the car breaks the frictional force caused by the strong man, but with his feet digging in and being pushed down from pushing back at the car, he counter acts the forces being pushed at him. The results are that since he has equal force pushing against the car he is able to stop the car moving at some point of time. So, it takes a few seconds for the strong man to stop the car.